1. Field of the Invention
This invention concerns folding hand tool sets, of the type used to hold sets of hex keys, screwdrivers, and similar hand tools.
2. Description of the Prior Art
The prior art in the field of folding hand tool sets includes a variety of tool sets, some with minor deficiencies, some with major. Three early sets are shown in U.S. Pat. Nos. Des. 156,677 issued in 1948; Des. 168,900 issued in 1952; and 2,804,970 issued in 1955. As reflected in all these patents, hex key tool sets were made of metal in the 1940's and 1950's, and the keys were held as in groups in holders.
Advances followed, as shown in U.S. Pat. Nos. Des. 332,211 issued in 1993, Des. 332,384 also issued in 1993; Des. 385,767 issued in 1997; 4,759,645 issued in 1988; and 5,791,211 issued in 1998. As in the last patent, a recent effort has been to form the tool set handle of fiber reinforced thermoplastic, in one piece, completely integral. Metal handles were criticized for corrosion, weight and cost. Two-piece plastic handles were criticized for lack of strength, and cost of assembly.